Give the definition for diffusion.

(A) gas molecules mix unequally average distance between collisions

(B) gas molecules escape from a container into a vacuum through a small hole

(C) gas molecules mix equally

(D) gas molecules spread out in a concentration gradient

option D.

Explanation:

The correct answer is option D.

Diffusion is the particle movement from high concentration to low concentration, such as air, water, etc.

Example: if you spray perfume spread throughout the room at one part of the fragrance scent.

The gas molecule thus spreads out in a gradient of concentration